Reproduction apparatuses typically include sheet feeding mechanisms to reliably feed individual sheets of media from a stack of media. For a given mechanism there is an optimum window, or vertical range, within which the top of the media stack must be presented to one or more feed rolls for reliable performance. This has been traditionally achieved using an elevating plate and associated elevating mechanism for raising and lowering the media stack to position the top of the media stack within the optimum window relative to the feed rolls. In the operating mode, a nudger roll, also commonly referred to as a pre-feed roll, is positioned above the media stack in contact with the top of the media stack. Rotation of the nudger roll engages the top sheet of the media stack, causing the sheet to begin moving from the media stack to a feed path.
In addition to the use of an elevating plate, conventional media feeder mechanisms also rely on the use of solenoid with the nudger roll. The solenoid operates to lower the nudger roll from an up position above the top of the media stack to a down position engaging the top of the media stack. The operations of an elevated plate mechanism and nudger roll solenoid are coordinated. With the elevated plate in a lowered position and the nudger roll in an up position, an operator can add media to the media stack.
To allow for increased media capacity, feeding mechanisms should accommodate reasonably large stack heights. Larger stack heights increase the complexity of both elevating plate mechanisms used to raise the media stacks and nudger roll solenoids. There are significant disadvantages associated with these mechanisms in the form of high manufacturing and maintenance costs.